Microsoft will give cloud customers a minimum of 12 months notification before discontinuing online services, or making any "disruptive" changes or upgrades, in an effort to standardize the support lifecycle for cloud-based software.

Microsoft will give cloud customers a minimum of 12 months' notice before discontinuing online services, or making any "disruptive" changes or upgrades, in an effort to standardize the support life cycle for cloud-based software.

Announced this week, the new policy ensures that WindowsAzure and Office 365 customers can plan for changes that would eliminate services, take them temporarily offline or require an overhaul of management practices.

"We are introducing a new concept we've named 'disruptive change,'" writes Microsoft program manager David Carrington. "Disruptive change broadly refers to changes that require significant action whether in the form of administrator intervention, substantial changes to the user experience, data migration or required updates to client software. A key aspect of the new Online Services policy is that Microsoft is committed to providing our customers a minimum of 12 months of prior notification before implementing potentially disruptive changes that may result in a service interruption."

Microsoft also committed to providing 12 months' notice before terminating any "Business and Developer-oriented Online Service," and also to preserve customer data for at least 30 days in renewals or migrations that involve customers moving off a service.

An example of a less drastic change that would receive a year's notice would be a "required upgrade to Microsoft Outlook to ensure continued functionality with Microsoft Exchange Hosted Services prior to the change actually occurring with the cloud-based service."

"In some scenarios, customers may have deployed on-premises software that is connecting to a Microsoft Online Service," Carrington continues. "In such situations, customers may need to implement changes to their on-premises software for it to remain operable with the Online Service, but the timeframes of Mainstream Support and Extended Support for the on-premises software remain intact and unchanged."

The policy applies to "regular maintenance and service updates," and not security problems, which are fixed as soon as possible.

Microsoft has argued that it can provide a more stable and predictable experience for cloud software customers than its rival Google can with Google Apps. This policy change helps put that promise into writing, giving Microsoft's cloud customers some of the same benefits offered those who buy the more expensive on-premise Microsoft software.

The one-year termination notice is perhaps more important in the world of cloud software than on-premise products, since customers who buy Microsoft's packaged software can continue to use it indefinitely, ever after Microsoft drops support. If Microsoft stops providing an online service, customers have to find an alternative.

Microsoft's general support policy promises at least 10 years of support for Business and Developer products, including five years of Mainstream Support.